INTRODUCTION. 9 



standpoint, but that need not deter the farmer from 

 becoming conversant with the entire subject, nor from 

 studying it in a scientific way. It is a subject which 

 has merited the careful attention of intelHgent land- 

 owners and of eminent hydraulic engineers. 



The profits accruing from the drainage of fertile land 

 are of two kinds : first, the increased yield of grasses, 

 cereals, and fruits which has a direct money value to 

 the producer; second, the increased healthfulness of the 

 community where drainage has reclaimed all of the 

 waste land. This latter has a money value which is 

 difficult to measure. The following example clearly 

 illustrates both of the above statements: 



The Indiana Bureau of Statistics made an investiga- 

 tion of the influence of tile-drainage on health and 

 crops, selecting a single township in the State where 

 drainage was one of the marked improvements, and 

 taking a period of five years before drainage began, 

 and five years after most of the township had been tile- 

 drained. By consulting farmers who lived in the town- 

 ship during both periods, they found that the average 

 crop of wheat in the five years before drainage was 9I 

 bushels per acre. The same land after drainage for 

 five consecutive years produced an average of ipj 

 bushels per acre. The average yield of corn in the 

 first five years was 31 J bushels per acre. In the five 

 years after drainage the average yield was 74J bushels 

 per acre. The physicians who answered calls in the 

 township were requested to report from their books, 

 and it was found that in the first five years there had 

 been 1480 cases of malarial disease. In the second 

 period there had been only 490 cases of malarial dis- 



